As is known and appreciated, the insertion of orthopedic screws or drilling of holes by a surgeon in peri-orbital, peri-cranial and other small bone applications typically entails the use of a non-powered, manually driven device. As is also known and understood, such insertions, whether it be for reducing fractures or for stabilizing fractures, customarily involves the surgeon--to insert the orthopedic screw, utilizing both hands--and at least one other person--to retract the wound area. Obviously, a savings in cost could result if the procedure could be accomplished by the surgeon acting alone, a savings in time could result where the surgeon did not have to communicate his or her instructions to that nurse or other person, a reduction in possible confusion could follow from eliminating the possibility of misinterpreting those instructions, and a savings in occupied space in the operating room could be had. If, at the same time, such a device could be designed ergonomic for comfortable and easy handling, with high degrees of tolerance for use at the exposed facial, or cranial, or other bones, and to be both sterilizable and autoclavable, a surgical device of such type would be highly desirable.
Recognizing that in use, the surgeon could then use one hand to retract the wound, and the other to hold the instrument in fashion to permit the driving of these orthopedic screws, or the drilling of holes into bone, it was realized that an essential feature of the instrument would have to be an ability to transfer a motion from the hand to a rotating motion for driving the screw into the bone. This led to an analysis of various squeeze-ratchet type assemblies, wherein the actuating of a pistol grip handle could produce a rotary torque for a 4 mm, 5 mm or similar orthopedic screw employed or to a mounted twist drill. Investigation led to possible devices for use, of a type set forth in U.S. Pat. Nos. 4,249,617 to Cox and 4,524,650 to Marks. Putting aside the fact that their disclosures were of assemblies that could rotate the screw in a direction to loosen it, as well as to tighten it (something which is not of significance in the surgical use intended for the present invention), there also came an appreciation that those devices allowed for a great deal of "wobble" and instability in the rotary motion imparted--something which could not be tolerated where only micro-movement is allowable; otherwise, a larger hole could very well be made in the bone than is required to fix the screw in place, with the result being that such a fixation could not really be used. Were this not bad enough by itself, further disadvantages with these described assemblies included an added "wobble" which resulted in a measurable loss of concentricity in rotational motion. Additionally, their manners of operation fail to adequately provide that desired "feel" to the surgeon, that the screw is successfully setting in the bone, so as to minimize the possibility of overdriving the screw in place where that type of tactile feedback is missing.